Question

write the definition and the formula for each statment

8. KINETIC THEORY AND MOLECULAR

PHENOMENA RELATED TO BIOLOGICAL PROCESSES:

kinetic theory of matter; ? molecules;?

diffusion;?

osmosis;?

dialysis;?

transport across living membranes;?

laws of gas transport; cohesion and adhesion;? surface tension; capillary action; viscosity;?

adsorption and absorption;? respiratory system ?

write the definition and the formula

Answer 1

• Kinetic theory of matter :-  It states that matter is made up of small particles called atoms which are in random motion and has two principles.Kinetic energy and potential energy.
• DIFFUSION:-

​​​​ The process of movement of substances from a region of high concentration to the region of low concentration is known as diffusion.

For example, if a bottle of ether or perfume is kept open then the gas molecules are diffused to outside.

• OSMOSIS:-

The process of movement of water molecules from the region of high concentration to region of low concentration through a semipermeable memberane is called osmosis.It is carried out by construction an osmometer.

• DIALYSIS: -The process of separation of substances by means of their diffusion rates through semipermeable memberane in a solution is called dialysis.

​​​​​​​ It is aslo defined as a process of removing waste and excess substances from the body.

• Transport across living membranes :- All living cells are enclosed by a memberane and molecules pass through them either by diffusion or active transport .

​​​​​​​

• Surface tension :-  It is the force of attraction through which surface molecules are held together.

​​​​​​​    Formulae: T = F/L

  where T is surface tension ,F is force acting per unit length,L is the length in which force acts.

• Capillary action :- The ability of movement of liquid through narrow spaces due to intermolecular forces(cohesion,adhesion).
• Viscosity:- The resistance experienced by the movement of one layer of liqiud over another layer is called as viscosity.

η = ( πPr⁴/8VL)t

• Absorption :- The process of absorbing molecules or ions into cells ,tissues or organs by means of osmosis or diffusion is known as absorption.Absorbtion is also known as a route through which substances enter into the body.
• Adsorption :- The process by which molecules or ions adhere (fix) to the surface (of adsorbent) is known as adsorption.It is a surface phenomenon.

  

• Respiratory system:- It is a set of organs through which a person breathes or exchange gases (oxygen , carbon dioxide) throughout the body.